Microsoft TypeScript 0.9 Updates Compiler, Adds Generics Support

Microsoft announced the release of TypeScript 0.9, which features a re-engineered compiler and support for generics.

Microsoft has released version 0.9 of its TypeScript programming language, which is a superset of JavaScript.

Microsoft officials said TypeScript 0.9 represents the largest update to the language to date, since Microsoft released the initial version of TypeScript last October.

The new release delivers significant changes to the language, compiler and tools. These span from highly requested new language features like generics, to a new compiler infrastructure that lays the foundation for TypeScript tools scalability, to hundreds of bug fixes and general improvements, said Jonathan Turner, a program manager with the TypeScript team at Microsoft, in a blog post.

TypeScript 0.9 is aimed at making it even easier for developers to build large applications with the language. "Over the past few years, we've seen JavaScript applications for the Web, on the server and on Windows become much more substantial in size," said S. Somasegar, corporate vice president of Microsoft's Developer Division in a blog post.

TypeScript enables application-scale JavaScript, providing high-fidelity interaction with existing JavaScript libraries, and giving developers the direct power and flexibility of JavaScript from a language that supports advanced tooling and error detection, Somasegar said.

And with the 0.9 release, "along with important new language features and improved tooling capabilities in Visual Studio, we've done considerable work to scale the TypeScript language service for large application development, giving developers a smooth, interactive experience regardless of project size," Somasegar said.

The introduction of generics to the language—the most-requested feature—improves developer efficiency. "Generics take advantage of the strong type inference that TypeScript already provides, allowing users to have better static error reporting and richer tooling, in many cases without any additional type annotations," Turner said.

In addition, the TypeScript compiler has been re-engineered, laying the foundation for great tooling scalability going forward, and provides a much higher-fidelity implementation of the TypeScript language specification, Turner said.

"The new compiler addresses over 150 issues reported on CodePlex since the 0.8 release. These include places where the compiler now catches potential errors more reliably, more accurate tools and general improvements across the board," Turner said. The new compiler has been designed to enable better incremental performance while editing code in integrated development environments (IDEs), he added.

Meanwhile, Somasegar noted that TypeScript has already been positively impacting Web development.

"Inside Microsoft, teams in Bing, Team Foundation Server,, CodePlex and elsewhere are using TypeScript in production applications, some in excess of 200k lines, leveraging TypeScript's ability to scale quickly with the assurances provided by a type system and rich IDE support," Somasegar said. "In the broader JavaScript community, projects like Turbulenz and Starling.js have leveraged TypeScript as part of new development libraries and kits. We're also seeing teams building enterprise and consumer applications for the Web, Windows Store and server—all with TypeScript."

Moreover, the TypeScript ecosystem continues to grow. Hundreds of developers are engaging with the project and more than a dozen editors now support TypeScript, enabling development with TypeScript in a variety of popular tools and across multiple major platforms, Somasegar said. TypeScript also won a 2012 Open-Source Rookie of the Year award.